76 below, the magnetite-garnetite exposures which have every appearance of belonging to a sheet-like body interposed between a floor of volcanic rocks and a partly removed cover of limestone. The lower boundary of the magnetite-garnetite against the underlying volcanics appears to be a comparatively even, though warped, plane, but the upper boundary against limestone is irregular, so that the thickness of the outcropping parts of the magnetite-garnetite mass varies from place to place. At the east end of the occurrence the magnetite-garnetite mass is well exposed in a steeply rising face. Over an area measuring 200 feet east and west and varying from 100 to 200 feet in breadth in a north-south direction, exposures are nearly continuous and there is a difference of elevation of more than 80 feet between the highest and lowest outcrops. The material is very largely granular-crystalline magnetite with only a slight admixture of garnetite. The upper boundary against the limestone, though not exposed, appears to be sharply defined. The lower boundary is against drift, but it is imagined that the contact with the floor of voleanic rocks does not lie more than a few feet below the lowest exposures of magnetite. To the west, along the south border of the occurrence, the outerop of magnetite-garnetite narrows and in a distance of about 600 feet the total thickness dwindles to about 10 feet or less and both the upper and lower boundaries are closely defined by outcrops of the limestone and voleanics. Still farther westward along the south edge, the thickness of the magnetite- garnetite body remains small, but is inferred to increase rather rapidly in a north direction to 20 feet and over. Over much of the south outcrop, the exposures are of garnetite and magnetite admixed in widely varying proportions. Along the north face to near the west end of the body, the magnetite- garnetite is widely exposed over a considerable height on the steep hill- side, so that the mass has the appearance of varying in thickness between 40 and 100 feet. The magnetite-garnetite in one stretch of 300 feet is exposed over a width of 100 feet or more. The difference in elevation between the outer, lower edge and upper, inner edge, is more than 100 feet. At the west end the body appears to be comparatively thin. The material is not uniform and in places is largely garnetite. Towards the northwest corner, a tunnel 130 feet long has been driven into the body. Along the tunnel the following succession is observable, the distance being measured from the tunnel mouth: O— 28 feet, mainly magnetite 28— 57 feet, mainly garnetite 57— 70 feet, mainly magnetite 70—100 feet, garnetite with some magnetite 100—130 feet, mainly magnetite A tongue-like area of garnetite and magnetite projects easterly into the central limestone area, from the southeast edge of the annular out- cropping area of magnetite and garnetite. This projection is 400 feet long and averages 60 feet in width. The outcrops are largely of garnetite, save towards the east end where magnetite is prominent. An isolated outcrop of garnetite and magnetite occurs 150 feet east of the east end of this tongue. Four hundred feet west of the mouth of the main tunnel is an outcrop of magnetite about 50 feet long and half as wide.